Vegetable oils are a far cry from “heart-healthy.”⁣ A more accurate name for vegetable oil is “industrial seed oil” as these oils are not derived from vegetables at all. For the sake of simplicity, throughout this post, I will be referring to this group of oils as “seed oils.”

These oils were only introduced to the human diet in the early 1900s. Prior to that, seed oils, like canola and rapeseed oil, were industrial byproducts. Once food manufacturers realized that these oils could be bleached, deodorized and chemically altered and then marketed as a cooking oil, the war on traditional cooking fats began.

What are industrial seed oils?

Seed oils are primarily made up of polyunsaturated fats (PUFAs). Polyunsaturated fats are fatty acids with many double carbon bonds (poly = “many”). The double bonds found in PUFAs are what make them more unstable and more susceptible to oxidative stress.  

These oils include:

  • 🚫 canola⁣
  • 🚫 corn⁣
  • 🚫 grapeseed⁣
  • 🚫 safflower⁣
  • 🚫 sunflower⁣
  • 🚫 rice bran⁣
  • 🚫 soy⁣bean
  • 🚫 rapeseed

How are seed oils made?⁣

Extracting “vegetable” oils from their source requires intense processing, chemicals, and often heat. ⁣

To make a seed oil, like canola oil, here are the steps:
Take rapeseed and clean, grind, pulverize, press, use a petroleum-based solvent like hexane to extract oil, boil at high temps (leading to oxidation), centrifuge, degum, bleach, deodorize (because the smell is awful and rancid), add preservatives and probably manufactured citric acid.

Now, let’s compare to how you make butter:

Take heavy cream and put it in a jar and shake until the fat solids separate from liquid. Maybe add a little salt.

This is a head-scratcher but which one do you think sounds like the food is more alive and the chemical structure of the foods more stable and in-tact?

This video is worth the watch as it shows in detail, the process of how canola oil is made:

We have been so completely duped into thinking that canola oil is healthier than butter. That’s the power of food marketing. Butter doesn’t have billions of marketing dollars behind it. But cheaply-made canola oil does.

The stability of our fats matters. Seed oils are unstable.

Food is a messaging system. The food you eat sends chemical messages to every cell in your body. “Messages” from these oxidized oils are so damaged, that the messages lead to DNA and cell damage, speed up the aging process, and contribute to chronic illness

The quality of the message matters. These oils just aren’t capable of sending health-promoting messages to your cells

Thankfully, in the last decade or so, more and more research is starting to surface shedding light on the truth about the health of saturated fat and the detrimental effects of polyunsaturated fats from seed oils. For example, a 2014 meta-analysis (a meta-analysis is a study of many studies) showed there are no benefits to overall health from reducing saturated fats or increasing the intake from seed oils.

avoid these toxic oils: canola oil, vegetable oil, soybean oil, sunflower oil, grapeseed oil, safflower oil, ricebran, corn oil

⁣Poly-unsatured fats lower cholesterol but they don’t prevent heart disease.

⁣Yes, it’s true that PUFAs lower cholesterol.. But cholesterol isn’t the actual driver of heart disease. That theory is based on faulty observational studies conducted in the 60s and 70s.⁣

Take a look at the Minnesota Coronary Experiment, one of the largest, controlled experiments on PUFAs and cholesterol.⁣ This is one of the most thorough, well-designed studies we have on fat and heart disease.

In this study, PUFAs did, in fact, lower cholesterol.⁣ But did the high-PUFA, cholesterol-lowering diet reduce mortality? Big fat no. And isn’t *not dying* the point? The study actually showed that the more a person’s cholesterol dropped, the more likely they were to die.

The idea that we need to lower cholesterol is not built on solid ground. Humans need cholesterol. It strengthens cell membranes and you need it to make vitamin D, cortisol, estrogen, and testosterone.

What about LDL is “bad” and HDL is “good” though? The truth is that neither LDL nor HDL cholesterol is always good or always bad. Good and bad depend on the particle’s composition. That depends on what you’ve been eating.

Do you think a diet high in rancid PUFAs is going to make for better cholesterol particle composition? Absolutely not.⁣

In fact, research is showing that oxidized fatty acids from industrial seed oils may play a pivotal role in developing cardiovascular disease.

Other researchers are connecting the role of seed oils in developing cardiovascular disease in that they inhibit processes involving vitamin K2, a nutrient essential for heart health.

polyunsaturated fats and thyroid health

Industrial seed oils are primarily unstable poly-unsaturated fats that wreck your thyroid.

One of the most important things you can do to optimize your health and metabolism is to remove foods high in polyunsaturated fats (PUFAs) from your diet. The greatest source of PUFAs in modern-day diets is industrial seed oils. PUFAs are highly unstable oils and react easily with light, heat, and oxygen.

Also, PUFAs are everywhere in our food system. The vast majority of packaged, processed foods contain high amounts PUFAs and the primary cooking oils used in all restaurants are some form of PUFA, like canola or soybean oil.

The double bonds found in PUFAs are what make them more unstable and more susceptible to oxidative stress.  

The oxidation of these oils creates free radicals when exposed to oxygen, heat, and light and then they steal electrons from other molecules, creating even more unstable molecules. This cascade effect creates a chain reaction of free radical damage that can suppress thyroid function by:

  • Blocking enzymes that produce thyroid hormone
  • Blocking proteins that carry thyroid hormone
  • Impairing a cell’s ability to respond to respond to thyroid hormone

PUFAs from seed oils drive disease:

Not only do polyunsaturated fats from seed oils wreck your thyroid, but they are connected to a myriad of other chronic illnesses. Consumption of PUFAs from seed oils can:

avoid these toxic oils: canola oil, vegetable oil, soybean oil, sunflower oil, grapeseed oil, safflower oil, ricebran oil, corn oil

How to avoid industrial seed oils:

1. Stop using the seed oils listed below:

🚫 Sunflower oil
🚫 Grapeseed oil
🚫 Flaxseed oil
🚫 Walnut oil
🚫 Canola oil
🚫 Corn oil
🚫 Soybean oil
🚫 Safflower oil
🚫 Wheat germ oil
🚫 Almond oil
🚫 Cottonseed oil
🚫 Shortening
🚫 Margarine (obviously)

Nuts and seeds are also high in polyunsaturated fats. While having a few sprouted, organic almonds here and there is not problematic, downing half a jar of almond butter is not a good idea. The fats in nuts and seeds are fragile and oxidize easily. In nature, these fats are protected by vitamin E, but by the time the nuts reach your plate, that vitamin E is mostly oxidized itself. Furthermore, eating large amounts of nuts and seeds is not aligned with a traditional diet, as the large amount of time and energy it would have taken our ancestors to get the nuts out of the shell was not worth the small amount of nutrition they provide.

2. Prioritize these fats instead:

Unlike polyunsaturated fats, saturated fats are very stable. They can withstand higher heats and are more stable when exposed to light and oxygen. More stability means less oxidation means more healthy for you overall.

Coconut oil
✅ Grass-fed butter (you can find raw butter through or look for a brand that’s 100% grass-fed)
Cocoa butter (great for baking)
✅ Lamb tallow
Beef tallow
Olive oil (not with heat!)

This post covers the best fats for higher heat cooking.

3. Cook at home and eat out less.

Unfortunately, the vast majority of restaurants cook with vegetable oil, canola oil, soybean oil, or some combination of the above. Even so-called health food restaurants who market that they don’t use canola oil, will replace canola oil with sunflower oil or grapeseed oil. All of those oils are problematic. To make matters worse, restaurants typically reheat the same batch of oil over and over, exponentially increasing the amount of oxidation those oils undergo.

Cook at home more so you have control over which oils go into your body.

4. Stop eating processed foods. Read your food labels.

Again, most processed foods and even foods marketing as “healthy” use industrial seed oils. These oils are often one of the main ingredients in that packaged food! Get familiar with reading labels. The more you practice, the easier it becomes.

5. Switch to grass-fed meat.

Grain-fed meats are fed corn and soy and the PUFAs accumulate in their tissues. When you eat the meat, you’re also eating an abundance of these polyunsaturated fats. Grass-fed meats have a much healthier fatty acid profile and are higher in nutrients like CLA than grain-fed meat.

5. Limit poultry and pork (or look for corn and soy-free)

Like grain-fed beef, most poultry and pork in the US are fed a grain, corn, soy combination and often fed things like corn and soybean oil to fatten the animals up. Even pasture-raised chickens are often supplemented with corn and soy. This feed changes their fatty acid composition making their meat far higher in PUFAs, and therefore, more inflammatory.

Limit your consumption of poultry and pork. If possible, source corn and soy-free poultry and pork. Northstar Bison is a great option for this.

6. If you can’t get grass-fed, choose leaner cuts.

If grass-fed meat and corn/soy-free chicken is not within your budget, choosing leaner cuts of meats ensures you’re eating less of the animal fat that is more PUFA-dense.

7. Consider a high-quality vitamin E supplement to protect from PUFAs.

Vitamin E can reduce the oxidation of lipid membranes caused by PUFAs and protect against lipid peroxidation. It can also increase the conversion of linoleic acid (PUFA) into more stable saturated fats. On top of that, vitamin E helps protect the skin from ultraviolet sun damage made more susceptible to damage by a diet overloaded in PUFAs.

My go-to vitamin E is PUFA Protect from Mitolife (Code CKN15 for 15% off).

avoid polyunsaturated fats for optimal health

Questions about PUFAs and taking the first steps to optimize your metabolize? Send me a message or ask in the comments below!


  1. Fatty acids, inflammation, and asthma
  2. Dietary lipids and risk of autoimmune disease
  3. A Fat to Forget: Trans Fat Consumption and Memory
  4. Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73)
  5. The Omega-6/Omega-3 Ratio and Dementia or Cognitive Decline: A Systematic Review on Human Studies and Biological Evidence
  6. Soybean Oil Is More Obesogenic and Diabetogenic than Coconut Oil and Fructose in Mouse: Potential Role for the Liver
  7. Omega-6 vegetable oils as a driver of coronary heart disease: the oxidized linoleic acid hypothesis 
  8. Medicines and Vegetable Oils as Hidden Causes of Cardiovascular Disease and Diabetes
  9. A host-microbiome interaction mediates the opposing effects of omega-6 and omega-3 fatty acids on metabolic endotoxemia
  10. Marked elevations in pro-inflammatory polyunsaturated fatty acid metabolites in females with irritable bowel syndrome
  11. Home use of vegetable oils, markers of systemic inflammation, and endothelial dysfunction among women
  12. The effect of various intake levels of soybean oil on blood glucose and inflammation in mice
  13. Relationship of omega-3 and omega-6 fatty acids with semen characteristics, and anti-oxidant status of seminal plasma: A comparison between fertile and infertile men
  14. Vitamin E function and requirements in relation to PUFA
  15. Relationship between vitamin E requirement and polyunsaturated fatty acid intake in man: a review

Important notes:

I am not a doctor, and I don’t claim to be one. I can’t prevent, treat, cure or diagnose illness or disease. The information presented on this website is not meant to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice, treatment or diagnosis. The purpose of this website is to share knowledge from my research and experience. I encourage you to make your own decisions regarding your health care based on your own research and relationship with your health care professional.

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